# CVE-2021-1134: Cisco DNA Center Certificate Validation Vulnerability

> An attacker can bypass certificate validation to intercept and modify sensitive network client data between DNA Center and ISE.

- **Severity:** High 7.4 (`CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 29 Jun 2021
- **Updated:** 7 Nov 2024
- **Also known as:** GHSA-c46x-8q9c-r3vx

## What is CVE-2021-1134?

CVE-2021-1134 is a high-severity vulnerability in Cisco Digital Network Architecture Center (DNA Center), published on 29 Jun 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the Cisco Identity Services Engine (ISE) integration feature of the Cisco DNA Center Software could allow an unauthenticated, remote attacker to gain unauthorized access to sensitive data. The vulnerability is due to an incomplete validation of the X.509 certificate used when establishing a connection between DNA Center and an ISE server. An attacker could exploit this vulnerability by supplying a crafted certificate and could then intercept communications between the ISE and DNA Center. A successful exploit could allow the attacker to view and alter sensitive information that the ISE maintains about clients that are connected to the network.

Weakness: CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2021-1134?

It affects 1 product.


Products: Cisco Catalyst Center.

## How do I fix CVE-2021-1134?

No fix has been published for CVE-2021-1134 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-1134 being exploited?

There is no known exploitation of CVE-2021-1134 in the wild and no public exploit code.

## Other vulnerabilities in Cisco Digital Network Architecture Center (DNA Center)

- [CVE-2021-1264](https://insights.sbomify.com/CVE-2021-1264/): Cisco DNA Center Command Runner Command Injection Vulnerability (critical 9.6)
- [CVE-2023-20055](https://insights.sbomify.com/CVE-2023-20055/): Cisco DNA Center Privilege Escalation Vulnerability (high 8.0)
- [CVE-2021-1265](https://insights.sbomify.com/CVE-2021-1265/): Cisco DNA Center Information Disclosure Vulnerability (high 7.7)
- [CVE-2026-20191](https://insights.sbomify.com/CVE-2026-20191/): Cisco Catalyst Center Arbitrary File Read Vulnerability (high 7.5)
- [CVE-2024-20350](https://insights.sbomify.com/CVE-2024-20350/): Cisco Catalyst Center Static SSH Host Key Vulnerability (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-1134 and fix it if it is affected.

What it is: CVE-2021-1134 is a high-severity vulnerability in Cisco Digital Network Architecture Center (DNA Center), published on 29 Jun 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-1134 in the wild and no public exploit code.

Affected product: Cisco Digital Network Architecture Center (DNA Center). No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-1134/ (Markdown: https://insights.sbomify.com/CVE-2021-1134/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-1134
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-1134
- OSV: https://osv.dev/vulnerability/CVE-2021-1134

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-1134/
Summaries are generated and may contain mistakes; the official description above is the record.